Automatic power tongs



Feb. 9, 1954 D. R. CORMANY 2,668,689

AUTOMATIC POWER TONGS Filed NOV. 7, 1947 9 Sheets-Sheet 1 I mi as H. whim-[W- i INVENTOR. DAV! Feb. 9, 1954 D. R. CORMANY AUTOMATIC POWER TONGS 9 Speets-Sheet 2 Filed Nov. 7. 1947 IN VEN TOR.

- 9 S heets-Sheet 3 Feb. 9, 1954 DR. CORMANY AUTOMATIC POWER TONGS Filed Nov. 7, 1947 INVENTOR. C MA/vx.

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Feb. 9, 1954 D. R. CORMANY 2,668,689

AUTOMATIC POWER TONGS Filed Nov. 7, 1947 9 Sheets-Sheet 4 IN V EN TOR.

Feb. 9, 1954 D. R, CORMANY 2,668,

AUTOMATIC POWER TONGS Filed Nov. 7, 1947 9 Sheets-Sheet 5 i 154 i T? 24 i g4 Feb. 9, 1954 D. R. CORMANY 2,668,689

AUTOMATIC POWER TONGS Filed NOV. '7, 1947 9 Sheets-Sheet 6 Feb. 9, 1954 D. R. CORMANY 2,668,689

AUTOMATIC POWER TONGS Filed Nov. 7, 1947 9 Sheets-Sheet 7 INVENTOR.

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Feb. 9, 1954 D. R. CORMANY 2,668,689

AUTOMATIC POWER TONGS 9 Sheets-Sheet 8 Filed NOV. 7, 1947 IQTTORNEY.

Feb. 9, 1954 D. R. CORMANY 2,668,689

AUTOMATIC POWER TONGS Filed NOV. 7, 1947 9 Sheets-Sheet 9 FUTUENEV Patented Feb. 9, 1954 I AUTOMATIC POWER TONGS David R. Cormany, Long Beach, Calif., assignor to C & Tool Corporation, Long Beach, Calif., a corporation of California Application November 7, 1947, Serial No. 784,556

13 Claims.

My. invention relates to power operated tongs or a mechanically driven wrench assembly par-v ticularly adapted to assemble and disassemble strings of tubing, casing, liners, drill pipe and the like, such as is used, for example, in oil wells.

'My power wrench is especially adapted for coupling and breaking up externally smooth, cylindrical pipe sections which thus lack tool engaging surfaces and it is also of particular utility in unscrewing joints in which the threads have become rusted tight or frozen.

The invention provides two sets of circumferentially disposed gripping members, axially spaced apart along a common pipe-receiving aperture, one set being adapted to hold the pipe alternatively against rotation in either direction, while the other set is designed to both grip and turn the pipe alternatively in either direction and oppositely to the direction in which the first named set holds its part of the pipe, the two jaw assemblies being arranged to simultaneously move toward or away from each other axially as may be required for threading or unthreading an engaged pipe joint.

An important object of the invention is to provide a substantially self-operating assembly of the type described, which is of both simple and sturdy construction, and of easy and efficient operation.

Another purpose is the provision of a positive drive mechanism operable through one set of engaging jaws to rotate a pipe alternatively in either direction while another set of jaws holds an adjacent pipe section against rotation in the same direction. A unique feature of the invention resides in gripping jaws employing bifurcate engaging cams adapted selectively to bind a pipe for or against rotation in either direction.

'S'till another object is to provide a mounting structure for the wrench assembly described, by which the latter may be accurately located above a drill hole or the like and may be tilted in any direction as well, in order to align its axis with that of a slanted-pipe which it is desired to grip.

Other objects and advantages of the invention will be apparent from the following description and. claims, the novelty consisting in the features of construction, combination of parts, the unique relations of the members and the relative proportioning,disposition, and operation thereof, all as more completely outlined herein and particularly pointed out in the appended claims.

' In the drawings, which form part of the present specification;

"Figure 1 is a side elevational view of my adjustable power pipe wrench assembly in operative' position;

Figure 2 is a side elevational view partly in section of my assembly shown in Fig. 1 in inoperative position ready to receive a pipe elevator under the coupling;

Figure 3 is a top plan view of my assembly as seen along the line 3-3 of Fig. 2, except the gripping elements are in the operative position for assemblying a string of pipe;-

Figure 4 is a longitudinal, vertical, sectional view taken through the axis of the pipe aperture as seen along the line 4-4 of Fig, 3;

Figure 5 is a sectional view through the assembly as seen in the direction of the arrows 5-5 in Fig.4;

Figure 6 is a horizontal, sectional view of the lower pipe-engaging elements as seen along the line 6-6 inFig. 4;

Figure 7 is a detail view of a pipe engaging die;

Figure 8 is an end elevational view of the assembly as seen along the line 8-8 of Fig. 2;

Figure 9 is a view similar to Fig. 6 showing the jaws in pipe gripping position;

Figure 10 is a side elevational view of an alternative assembly of the assembly shown in Fig. 2, with an added attachment for assembling and disassembling couplings in a string of pipe;

Figure 11 is a plan view of the assembly shown in Fig. 10 in operative position of the added attachment;

Figure 12 is a side elevation of another alternative assembly of the assembly shown in Figure 2, especially applicable to portable derricks;

Figure 13 is a side elevational View of another alternative assembly of the assembly shown in Figure 2 in inoperative position;

Figure 14 is a side elevational view of the alternative assembly shown in Figure 13 in operative position;

Figure 15 is a side elevational View of another alternative assembly of the assembly shown in Figure 2, in inoperative position;

Figure 16 is a bottom view of my assembly shown in Figure 15 as seen along the line l6-l6 of Figure 15;

Figure 17 isa fragmentary view partly in top plan and partly in section showing in full lines one of the pipe gripping assemblies at the instant of engagement with a pipe and showing in dot and dash lines the position of the pipe gripping assembly after being wedged into engagement with the pipe; and r Figure 18 is a sectional view taken in the difeet 24 (four in number) serving to brace the upe right upon a horizontal platform ,26 whicnis sup:v

ported upon the end cross pieeeitfindiritermediate cross piece 20 of the frame.

The upright 22 is composed of an inner, hollow,

open-topped cylinder 28 provided with an aper ture 30 near its base for the introductionlof pressurized fluid therein. An elongated cap 32 is slidably mounted atop the cylinder and is threadedly attached at its lower end to agmediallylocated tubular collar 34 circumposedonthe cyl-' inder 28 and thus simultaneously longitudinally slidable therealong together with. the cap. Located within the cylinder is asnugly fitting piston 36 having an upwardlyextending shank 38. terminating in an annular bearing disk M] which is adapted for rotational registration with the inner face of the end of the cap 32.

In a terminal, circular recess formed within the upper mouth of the cylinder there is positioned a shank-engaging packing gland 42, while an annular casing 64 disposed about the lower portion of the cylinder 28 provides a fixed support for the slidable collar 34 whenthe latter is at its lower or retracted position, shown inv Figure 2. By this construction, it will be seen that bydraulic fluid such as oil or thelikeintmduced into the cavity of fixed cylinder 28 at aperture 30; will force upward the piston 35 together with attached cap 32-,and collar 34 while at the same time permitting thelast two to be rotated at will, any desired degree about the upright, as shown in Figurel Upon release of fluid pressure in the sliding cylinder, the Weight of the elevated assembly will retract the connected members un-. til the lower end of the-collar again abuts against the upper edge of the casing 44.. (See .Figure .2.)

In this lower position the coupling BI ,is ready to reecive the hoistingelevators (not shown), and the pipe 80 is supported by the slipfiinot shown).

Secured to the lower portion of the telescoping collar 34, a rigidhorizontal bracket tiiis attachedin turn to a pair of diverging, upwardlyslanted struts i8 and 50, each of which-fixedlysupports on its outer end, a, horizontally disposed, cylindrical sleeve Hand '54 within each of which sleeves is slideably and rotativelyv mounted a longitudinally reciprocable arm 56 and 58 of con-. siderably greater length: than the respective sleeve. The inner end of each arm is provided with an enlarged head or flanged nut Soto thus. limit travel of the arm within its sleeve, while the opposite end of the arm is integrally attachedfto the upper section of a vertically disposed,,open topped cylindricalchamber 52 resembling .a dash pot. Within the chamber .is mounted va corree. spondingly shaped plunger fi ihaving ,a depend ent, axially reduced stem 5.6 insertedpartway within a helical spring fiflwhichlatter has its fixed seat at the base ofithechamber' and.bears against the botttom of the plunger. atitsother end. Helical. springs .67. andAfiS are disposedspn arms 56 and 58 between cylindrical sleeves '32 and 54, and cylindrical chambers 62, for the purpose of urging arms 56 and 58 outwardly to cylindrical sleeves 52 and 54.

Atop each plunger 64 is mounted a generally U-shaped bearing support 10 and 12 adapted to journal therein the bearing ends TI and 19, respectively, a pair pf bearin s J3 anclfis. Bearings Band 15 are provided pvithdoores-fiii 311C118], respectively, which are adapted to journal therein a pair of horizontally projecting trunnions H and I6 which support the upper gripping unit 18. By: this construction, the position of an engaged pipe .80 need not ,be aligned with the upright 22 but may (be held atan angle diverging considerably 'therefromwsince, the pipe, together with its engaging unit, can rotate on the horizontal axis ofthetrunnionsand can also tilt longitudinally alonglthis same axis, as best shown in Figure 8, by rotation of bearing ends 11 and 79 in their respective U-shaped bearing supports 19 and 12, since each plunger-'64 is'capable or independent vertical movement in its chamber-,--wh'ile' the plunger assemblies can; in turn; rotate on the" axis of the vextension arms 56 and58. In-ad dition, the whole unit can; be adjusted vertically by the fluid controlled upright22, andcan ='-be moved toward and away from 'the-'-uprightby the sliding extension arms 56 -and'58.

The wrench assembly 18"whichis ;,carried-bythe trunnions wand 16, is located ina"gener ally cylindrical housing having a rectangularrre cess 82 at one side thereof and; formed of tintegral side 84 andjbottom walls flfi'with'a flat top; 8.8v bolted thereto, the top and ;bottom walls being; centrally apertured in their annular sections "to receivea, vertical pipe 480 therethrough; The in:- ner ends of. trunnions 'i' llandflfiam integra l connection to side 84 ofithe. wrench assembl 38; as best shown in Figuresl, 2,3;andj8. Attached to the outer faceof the side .wall 90 (of the :rec: tangular portion 82, of. the wrench ,lhousing a. projectingbracketflz whichsuppor'ts a wrench: driving motor 94 of: conventional;construction! A horizontally disposed wormgear 96 .locatex'liin the recessed section .82 of the, ,wrench'. housin is operatively connected ,tothe motorby means, ofv an intermediate gear train 98 llocatedinarec-i tangular container or gear box I00 wh'iehlistaie fixed to the-end of the worm zhousing,thegear train consisting ofa driving pinionsgearJUL-fans intermediate-gear I04 and high J05 ,andglowJ-DB. speed gears journalled .on the;worm,,shaft ,l lll= and alternately keyed thereto byr;..an-intermediate. jaw:clutch H2,- The shaft of the'drivi-ngpinion IE2 'isgconnectecl to the :driveshafit H 3 ioi the mo tor by;a coupling sleeve 1 l4 locatedputside .ther

sear box; the latter nit i szpompletedi in...-tum by a cover plate H5 bolted thereon. v

Rotatably mounted;wit hin the circular section oirthew housings-84 is, ahorizontally;dispQsedrringi ear-1 i5 havinginner and .outerperipheral te th; of which the latter are engagedjinidriving-asela: tionby the Wolf-mask} The rin searzis provided, with; a medial-,iannnlar. rib on ;bothiits;unper and: lower iaces..:the respective :ribs. :1 l 8 :andrl M ke-ins set in. corresponding raceiways iormedsinzthe topcover :plate 88 and :bottom; housing wallz'fiea'ndi supplied with ball: bearings 4 22. Above aniline low the plane of the ring-gear are located-await of inwardly extending, -annular,--rot-atable spacer plates, "of which-the lower 1 24 Tests upon'a ledge I25 formed by the inner perip'herypi the housing floor ;while the upper spacer plate I28 is D 30- vidediwith. an upwa d y, xtendin' ,,,annular he l 29 about its outer edge, which rib is receivedin 5" a corresponding groove or race way cast in the housing cover and also supplied with ball bearings I22.

Between the two spacer plates I24 and I28 are pivotally mounted a series of circumferentially spaced, cam-like, pipe gripping jaws I30 (three in number) provided with mutilated gear teeth I32 disposed in engagement with the inner peripheral teeth of the ring gear 0. Each jaw is vertically traversed by a bolt or pivot pin I34 attached by nuts I36 to the opposite spacer plates and the jaws are further provided with a pair of inwardly diverging fingers I38 and I39 which fan out in the shape of a V. At the end of each finger is mounted an inwardly bowed, knurledor toothed engaging die I40 held in place by pin I4 I, shown in detail in Figures '7, 17 and 18, the curved face of the die I40 of finger I38 of each jaw I30 being oppositely mounted to the curved face of the die I40 of finger I39 of the same jaw, so that the dies I40 of fingers I38 of all of the jaws I30 can jointly engage a pipe for rotation in one direction while the dies I40 of fingers I39 of all of the jaws I30 are adapted to engage the pipe for contrary motion. The pins I4I are securely mounted in fingers I38 and I39, and pass through passages I45 in dies I40. Passages I45 are considerably larger diametrically than pins I4I, so that dies I40 are loosely mounted in fingers I38 and I39. Thus pins I4I merely function as die keepers to keep dies I40 from falling out of their slots in the ends of fingers I38 and I39, and do not function to rigidly afiix the dies to the fingers.

The action of these dies I40 is entirely novel and produces very beneficial results as will now be made apparent. Viewing the apparatus from the top as in Figures 3 and 5, clockwise rotation of the ring gear H causes clockwise rotation of jaws I30, thus forcing dies I40 of fingers I39 into contact with pipe 80. Dies I40 of fingers I39 grip pipe 80 integrally as said dies are moved into contact therewith, and thereafter during clockwise operative movement of pipe 80 dies I40 of fingers I39 move as a unit with pipe 80. But the fingers I39 move forward independently of the dies I40 mounted thereon after these dies have contacted pipe 80 until the necessary gripping position is reached.

The way that one of these fingers I39 moves with relation to the die I40 mounted thereon is as follows:

If die I40 was of uniform thickness there would thus be no wedging action. However, to render such a wedging action possible, die I40 is thicker at one end, I43 (see Figures '7 and 1'7), and therefore the movement of the surface I41 of finger I39 which contacts the rear surface II of die I40 over the rear surface I5I of die I40 has a wedging action by having the effect of wedging or camming the outer end of finger I39 farther away from the center of the gripped pipe 80, and thereby wedging the die tighter against the pipe 80 and closer to the center of pipe 80. Corresponding surfaces I4! and I5I are complementarily shaped and may be either flat or respectively convex and concave.

Figure 17 illustrates a pipe gripping jaw I30 in two positions relative to the pipe 80. The position illustrated in full lines is that which is occupied at the instant the pipe is engaged by the die I40 on the finger I39. Continued rota tion of the ring gear H6 in clockwise direction will cause translation of the jaw I30 from the full line position to the position shown by the dot and dash lines. It will be seen that during this translation the die I40 on the finger I39 has not moved with the jaw I30 but that it has been wedged against the surface of the pipe 80. It will also be seen that the pin MI in the finger I39 has moved from one end of the slot I45 toward the opposite endof that slot.

After the desired gripping position has been reached pipe 80, die I40 and its associated finger move clockwise thereafter as a unit until clockwise rotative force is no longerapplied by ring gear IIG.

counterclockwise rotation of ring gear IIG causes counterclockwise rotation of jaws I30, thus forcing dies I40 of fingers I38 into contact with pipe 80. Counterclockwise rotation of the pipe is effected in exactly the same manner as clockwise rotation, except that dies I40 of fingers I38 grip and move pipe 80 instead of dies I40 of fingers I39.

In this way a large portion of the circumference of pipe 80 is engaged by dies I40 my dies I40 grip ping and positively engaging as much as forty (40%) percent of the circumference of pipe 80. Thus pressure is spread out over more of the pipe wall and crimping of the pipe is reduced to a minimum by this equalizing of the pressure.

A further advantage gained by my invention is that the pipe 80 is centered at all times so that the center of pipe 80 is equi-distant from each of the three pivot pins I34 in the make-up unit I8 and from each of the three pivot pins H0 in the back-up unit I42. This is accomplished in the following manner:

Each of the fingers I38 and I39 rides up the back of its die I40 against the wedge caused by the thickness I43 on the pipe gripping face of the die I40 a certain distance, namely far enough to cause the finger I30 or I39 to move as a unit with its die I40 and pipe 80. This distance may vary in all of the dies, due to differences in thickness and contour of pipe 80, and thus all variations in pipe 80 are accommodated by these wedges I43. In this way pipe 00 is always centered and the pivot pins I34 always rotate in circles whose center is the same as the center or axis of the pipe when pipe 89 is being rotated. Also the full face of each die I40 is always flush with the entire part of pipe 80 which it engages due to the universal mounting of the make-up case in opposed pairs of trunnions or roller bearings, i0, 'I2, 14 and I0. By these opposed pairs of roller bearings the make-up case can follow any deviation of the pipe 80 from the vertical and thus the make-up case, and hence the faces of all of the dies I40, are always at right angles to the axis of pipe 30.

The beneficial result obtained by thus always maintaining the dies I40 flush with pipe 80 is that the pressure of the tongs against the dies is always evenly distributed over the entire face of each of the dies I40 and the dies never bite into the pipe more at one point than at another. Thus these dies further help to minimize or eliminate crimping of the pipe by always being flush with the pipe due to this universal mounting Also lateral movement of pipe 80 with or without tilting is always followed by the case and dies due to the apparatus employed for mounting and suspension shown and described herein, which includes the horizontally pivotal mounting of collar 34 on upright 22 and the horizontally slideable mounting of arms 56 and 58 in sleeves 52 and 54.

Upon the jaws firmly gripping the pipe 80 (Figure 2) by reason of articulation ofthe inner 7? teeth of the ring :"gear ll6 with the geartteethi I32, the gripping jaws-pipe, and .spacerrplates are then :rotated :in. unison, 'byfurther rotation ofx'the ring gear inthe same direction;..driven by .theworm. 9'6.

Located beneath this wrench assembly. is a;.second gripping unit-I42, rotatable .with'ithe upper 'unit, I8 and vertically adjustable in relationthereto, so :as to. accommodate a pairof pipe sections being coupled. or-uncoupled fwhile suspended between the respective gripping. units. The lower unit: consists of .a pair of horizontally disposed, centrally apertured, fixed disks I44 and I46:each.having-extending ears I lIwhich are mounted on opposite endsyof vertically positioned tubular. spacers I48 thelatter being. longitudie nallytraversed .by dependent rodszl 52; .I 53,. and I54 secured to the undersurface of .the wrench housing 86. Below the jaw assembly I42, a helical. spring I56, I57 and .158 disposed about each rod I52, I53 and;I54 with its upper end bearingagainst the lower disk I46 and its lower extremity seated against a. flanged. nut I68 threadedly mounted'on the :bottom of the respective'rod; Similarly, above the jaw assembly I42 a-helical spring I55 is disposed about each rod I52, I53 and I54 with the extremities of .said springs seated to give resilience above the Jaw assembly I42.

Rotatablymounted between the disksld i and I46 is a horizontally disposed, internally-toothed, ring gear I62 having a laterally extending :operating arm I64 projecting therefrom. Ring. gear I62 may either be mountedsimilarly to ring gear H6 of upper gripping unit I8, or it may merelybe seated against the top ofdiskv M36 .as shown in Figure 4. Ring gear 'I 62 will'not move out of its path of rotation because of its contacts with outer cam teeth I61. Arm I6-iszalternately actuated to rotatethe ring gear I62 in opposite directions by a piston rodItI attached to a-piston I63 which is reciprocally mountedin a cylinder I65. Cylinder I65 ispivotally. connected between disks I44 and. I IB'of lower jaw assembly I42 near the peripheries of disks. I4 3 andME.

The piston I63 is part of the-hydraulic system shown particularly in Figures 3, 6 .and 9.

This hydraulic system utilizes fluid froma reservoir (not shown) to actuatezthe lifter legassemblyv (Figures 1 and 2), the worm motor (Fig-. ure and the backups or-lowergripping unit I42 (Figures 6 and 9).

To actuate the lifter 'legassembly'fluidfrom the reservoir is drawn through line IIS, threeway valve I78 and line I86 to aperture 36in. cylinder 28; To lower the lifter leg assembly fluid is withdrawn'from aperture 36 through line. I36, three-way valve I18 and .returnline .182 to.the reservoir;

Actuation of the three-way valve I78 is effectedby manipulation of lever I St. When lever I84 is in. it connects lines I76 and 186 and thereby lets fluid under .pressure from the reservoir .go into aperture 36. to raise thelifter leg assembly; When, conversely, lever :IM is .out it connects lines I86 and I82 and therebydraws fluid out of aperturetII into the reservoir to lower the lifter leg assembly,

To actuate the worm motor fluid from the res ervoir is fed through line I36, four-way valve I68 andline I96 to worm-motor 94 to rotate the worm gear in one direction, the fluidreturning to the reservoir through lines .I9'2='and I94..; To rotate the worm geartheopposite direction iii;

fluid :is .fed tO thSTWDI'm motor SI- through-Jine M6,; four-way valve I 88 .andline 1- I92 from the reservoir and returned to the reservoir through lines I 9Il-and I94;

Actuation: of the four-way valverl88 is effected by manipulation of lever I96." When lever I96ris in it connects lines I86 and I96 and thereby admits fluid under pressure from the-reservoir into wormimotor 94 to actuate its ringgear ina clockwise direction. 1 When, conversely, lever-I96 is out it connects lines I86 and I92 and thereby feeds fluid into wormmotor 9t fromthe reservoir to actuate the wormrmotors ring gear in a counter-clockwise :direction. I v

Synchronous actuationof the backups or lower gripping'unit .I42Jis efiectedwhen lever I96'is manipulatedv by connectingthe cylinder 165 ou opposite sides of piston; I 63 with the lines tothe worm motor 94. Line. lsajconnects line-I90 with the part of cylinder I that is on the side of piston. I63 that is opposite piston rod ISI. Line wilrconnects line I62'with thewpart of rcylinder I65 that houses pistonrod I51 Thus when fluidisfed from the reservoir through line I96 "to worm'motor 94 todrive'the .upper gripping unit; F8 in a clockwise direction fluid also flows along line I98 -to cause piston I63,.piston rod.I6I and arm I6 to effect counter-clockwise rotation of; ring gear I62 of lower gripping unit I42. 'When, on the other hand, fluid is fed-to worm motor 94 through line I92 to drive the upper gripping .unitin a counter-clockwise direction fluid is also fed through line 266 to the piston-rod side of cyle inder I65 to sheet clockwise rotationof ring ,gear I62. Inthis way, by'these means the lower. gripe pingunit I 42 is always automatically set at .a position opposed to the upper gripping unit "I8 by themere operation of manipulatinglvalve 166.

A series of pipe gripping jaws 166, similar .to jaws I 36 above, are pivotally mounted-between the two disks with their outer cam. teeth-I 6'! dis; posed in engagement with the internally -project-, ing teeth of the ring gear I62. Eachv jaw-is. DI'O-w vided with a pair of inwardly divergingflngers having 'an inwardly bowed, toothed or serrated gripping end I63 ;and I69, ,one or. the other of; the pair of fingers of each-jaw beingadapted to engage the pipe 86 in binding relation by movement about its pivot pin :I lib Disks M l-and Hi6 are provided with central passages to receive the drill pipe. The two disks are each outwardly flanged adjacent said centralpassages to provide raised portionsof the disks as showninFigure .5 and said; central passages are beveled so as to provide aguide way I12 for a pipe or coupling inserted therethrou-gh, froineither side, while,.in addition, eachdisk may be accurately slotted or apertured betweenthe jawspivot pins I76, as at II4.- It will thus be seen that by rotatingthe lower ring gear-I62 .in onedirection or the other by actuating the arm I64, the pipe 36 will be grasped by the one set of fingers I68 or I69, respectively,

and held to prevent rotation of the pipe against the angular alignment of the gripping teeth. The fingers I38 or I39 of the upper wrench assembly I8 are then moved against their adjacent pipe section by actuation of the worm gear 96. Continued actuation of the worm" gear 66 after the fingers I35 or I3 contact the pipe 86 causes the fingers I38 or I36 and thepipe 66 to be driven in counter direction-to the lower engaging fingers I68 or I69 to screw or unscrew. the upper pipe segment asxthe case'mayben To reverse the ac-: ti'on,'it is necessary;onlyto:manuallyzoperate the lever I96 on the four-way valve so as to extend the opposite engaging fingers (I68 or I 69) and then drive the worm gear in a contrary direction. The lower gripping assembly I42 supported by the resilient coils I56, I! and I58 will automatically travel up or down the vertical suspension rods I52, I53 and I54 as required in inserting or withdrawing a pipe section from a coupling joint.

The cases of the make-up (T8) and back-up (I42) units are the reaction members against which the rotation of the ring gears I I6 and IE2 is effected.

The beneficial result that is obtained by this utilization of v the reaction forces is that neither the make-up case nor the back-up case is braced against the ground and therefore both units can be suspended in the air in operative position without any brace or rope, i. e., neither compressive nor tensile, reaction bracing.

This is also a great safety factor as there is no back-up line in my tongs. In prior tongs the back-up line, or tensile reaction member was, liable to snap and cause the back-up tongs to violently spin around the pipe, often resulting in killing or injuring someone.

In the variation of my invention shown in Figures 15 and 16 the reaction force is transmitted from the make-up case through the lifter leg and hand tongs to the pipe and spider and slips which furnish the reaction force for the backups in this variation.

Figures 10 and 11 show an alternative embodiment of my invention in which the tongs are suspended from the top instead of from the bottom as in the embodiment shown in Figures 1, 2 and 3. An advantage of this embodiment shown in Figures 10 and 11 is that the tongs center more easily and work better. This embodiment employs cylindrical upright 22 with an elongated cap and associated tubular collar, similar to cap 32 and collar 34 of my preferred embodiment, slideably mounted over an upwardly slanting strut similar to one of struts 48 and 50 of my preferred embodiment helps provide rigidity to a tubular member integrally connected to and horizontally extending from the collar similar to col-- lar 34. A cylinder containing a spring which abuts against the bottom thereof and an associated plunger is integrally attached to an arm similar to arms 56 and 58. This arm is slideably and rotatably mounted in said tubular member. Spring 202 and yoke 204 stabilize the tongs which are suspended on the lower end of said plunger at 206 in such a manner that there is more weight to the right of point 205 in Figure 10 than to the left of point 205. This construction causes the yoke 204 to move up against spring 202 and there-- by the tongs are kept level by making the spring 202 strong enough to offset the overbalance. This construction leaves room for the hoisting eleva tors (not shown) to latch and unlatch above the tongs;

An added attachment consisting of a pipe wrench 208 mounted on a vertical post 2I0 is for screwing up and unscrewing couplings when it is necessary to replace the couplings in the string.-

This can be done with the embodiment shown in Figure 1 but it entails changing dies and this involves too much time and trouble. This attachment 208 is completely portable and is removed when not needed. It is much easier and simpler than changing the dies in the make-upassembly.

Flgure 12 shows still another embodiment alternative to that shown in Figures 1 and 2. The structure shown in Figure 12 is suspended from above like that of Figures 10 and 11 instead of being supported like the embodiment shown in Figures 1 and 2. However the embodiment shown in Figure 12 is suspended by a cable 2I2, which may be operated by a sand line drum (not shown), or by a cathead (not shown), or by a weight box (not shown), or by fluid pressure against a piston having a piston rod connected to cable 2 I 2, which is slideably mounted in cylinder 2I4 as shown in Figure 12.

Also three legs, 2I6, are integrally attached to and extend downwardly from disk I46 of lower gripping unit I42. Legs 2I6 rest on'the ground or floor in order to line hold the em-' bodiment of Figure 12 in inoperative position, when there is little or no tension on cable 2I2, and they are lifted to operative position as into gral parts of lower gripping units I42 when the tongs are raised by the cable 2l2. These legs 2I6 take the place of collar 34 in Figure 2 which rests on casing 44.

Figures 13 and 14 show another alternative assembly to that shown in Figures 1 and 2. Figure 13 shows this alternative in the inopera tive position with the extensions 2 I 8 of dependent rods I52 resting in the supporting sockets 220 which are integrally attached to a brace member; A spider 22I is also provided. Figurell shows this embodiment in the operative position with the extensions 2I8 of dependent rods I52 idly supported above the empty sockets 220. A cable 2 I2 supports this assembly in the same manner that the embodiment of Figure 12 is supported, bails 222 and 224 providing four points from which the tongs are suspended.

When the tongs shown in Figures 13 and 14 are in inoperative there is a double guide ring like I12 in Figure 4 for the pipe to move through when the pipe is slid through lower gripping unit I42. This double guide ring is rigidly braced by the tongs resting with legs 2 I8 in holders 220 as shown in Figure 13. This guides the pipe when it is passing through the tong assembly into or out of the hole of the oil well.

There are three such double guide rings in this assembly, one in the spider, one in the makeup unit and one in the back-up unit.

These guide rings keep the pipe better centered than a single guide ring would do as they do not serve as a fulcrum for tilting the pipe as does a single guide ring.

A coupling coming up may hit the guide ring (like H2 in Figure 4) in the spider 22I in Fig ure 13, which is integrally connected to the above mentioned base member that is setting loosely on the derrick floor. This may move the spider 22L together with its attached base member, laterally.

The tongs are resting in the sockets 22!} which,- together with the spider (Figure 13) 22L are in-' tegrally connected to the said base, so they move laterally with the spider and so all the centering rings move integrally laterally as a unit and thus the centering rings keep the tongs cena tered.

weight 2 I4 on one end and the tong assembly on the other, thus effecting a suspension similar to the assembly shown in Figure 12.

Wheel 223 is mounted on fork 220, which is mounted in post 226 so it can rotate on its thrust Figures 15 and 16 show another alternative 1! bearing 23!, which i mounted on a shoulder-in post- 226. This rotation swings the tong out: of

:thewayof the well head when desired.

Rollers 23B, mounted on ball bearings and preferably -three in number and: opposed, facilitate :the raising'and lowering of the assembly on the post 225. Supports 222 and 224- are' like'Figures Hand 1 only they are connected. to horizontal arm 232.

' Only two extensions 218 and sockets 22s are used and spider 22l is-also provided.

J-shaped guides 234' (four in number) are attached to the bottom 8t of make-up case 78 to center the tongs-on the pipe. A hand wrench (not shown) serveszas a back-upmember for the first few sections of pipe. After that the weight of Y the pipe itselfperforms this function and renders it unnecessary to'use hand tongs for back -ups? f'One of the prin'cipal'features of theassembly shown"in"Figures 15 and 16 is the provision of a d'ire'ct driven flexible shaft 235 (see'Figure' 16) which is connected to the driving pinion gear H12 in gear box IMF in place of'motor drive shaft H3, coupling sleeve l-l land motor 94 shown in Figure'5, whi'chare eliminated in'this assembly'.

This is the most simplified assembly shown in the accompanying drawings, as it eliminates the hydraulic drive shown in Figure as ex-- plainedabove andalso it eliminates the backups or-wer gripping unit I42, thus greatly reducingthe cost and the weight ofthe tong assembly. 'I'he flexible drive has a motor 237 and a conventional combination clutch and reverse gear 238 with a single-speed forward, and it is equipped with a torquemeter 2%- to measure the torque delivered to the threads of the pipe.

While I have shown and described in some detail several presently preferred embodiments of my reversible pipe-coupling wrench, it is to be understood that various modifications may be made in the construction and operation thereof Within the scope of the subsequently claimed invention.

I claim: Y

1. A pipe wrench assembly including a pair of pipe gripping units, coupling means for holding said units in axially spaced relation to each other, a plurality of pipe gripping elements pivotally mounted in each of said units, the several elements of each of said units being jointly operable to selectively engage and disengage a pipe against rotation in either direction, a reversible fiuid driven worm motor operable to jointly operate the several elements of one of said units, a reversible fluid operated piston in a cylinder operable to jointly operate the several elements of the other of said units, a source of fluid pressure and fluid lines and valve mechanisms to selectively simultaneously admit fluid pressure from said source to the respective opposite sides of said worm motor'and said piston, whereby said'units always are substantially simultaneously urged in opposite directions from each other in order to make or break a pipe joint.

'2. A pipe wrench assembly including a reversible-source of rotary power, a ring gear, a drive connection between said source of power and said ring gear, a pivoted pipe gripping member rotatable-on its pivot by said ring gear and a pair of pipe gripping .dies mounted on said pipe gripping member, said dies being disposed on opposite sides of a line between the axis about which said. pipe gripping member is. pivoted a d the-centralxaxis of" a pipe whichris to. beigrippe'd by said pipe gripping dies. i

3. J-Aspipe wrench assembly includingxat grip-'- ping unit having. a: pipesreceiving' passage therethrough, a :plurality of. pipe-gripping elements; each of which includes a pair .of gripping surfaces. operatively facing in opposite pipe-gripping directions, mounted in said unit, :means for-sub stantially, simultaneously rotating saicl unitand pivoting said elements in one :direction and means for substantially, simultaneously rotating said. unit and pivoting said elements in the op posite direction. V V

'4. A pipe wrench assembly includingapivoted pipe-gripping element; means for pivoting said element and a pipe-engaging die having -nonparallel pipe-engaging and rear-ward 'faces suffi'-; ciently-loosely mounted on said element to permit said pipe-engaging face to be wedgedinto and out of pipe-engagement with a' pipewhen said'pipe engaging fac is in operative engagement with a pipe.

' 5. Apipe wrench assembly including a-pi-voted pipe-gripping element having a forward face-and a pipe engaging die having non-parallel pipeengaging and rearward faces loosely mountedcn said element with said rearward face-disposedadjacent to said forward face, said forward and rearward faces substantially coinciding;

6. A pipe wrench assembly including a gripping unit having a pipe-receiving passage therethrough, a die finger carrier-ringdisposed about said passage and rotatably mounted in said'un-it, means for rotating said ringin a-forwarddirec tion, a plurality of die holdingfingers pivotally mounted on said ring and extending in a-dire'ction forward of th center'of said passage, a cam sur face on the end of each of said fingers, a pipe engaging die having-a pipe-engaging front face and a rearface loosely mounted on the end of each finger so that said rear face'and said forward cam surface are complementary and disposed adjacent to one another, the distance betweensaid faces being greater at one end of each die than at the-other end and the end of each die having this greater face separation being the forwardmost end of the die when said fingers and said dies are in the pipe-engaging position and means for simultaneously pivoting said fingers.

7. Apipe wrench assembly including a gripping unit having a pipe-receiving passage therethrough, a gripping element carrier ring disposed about said passage and rotatably mounted in said unit, means for-alternately rotating said ringinopposite directions, a plurality of pipegripping elements pivotally mounted in said unit, each-of which individually-comprises a bifurcate jaw a cam surface on the end of each furcation of said grippingelements, a pipe-engaging die having a pipe-gripping front face and a rear'face loosely mounted on the end of each of said'furcationsso' that said rear face and said forward cam surface, are complementary and disposed adjacent to one another, the distance between'said faces being less at one end of each die than at the other end andjthe ends of the two dies on each gripping element having this lesser face separation extending generally toward each other, and means for alternately pivoting all of said gripping elements in either direction.

8. A pipe Wrench ass.embly,"including a base member, a laterally extending supporting arm aflixed to said base member, a. gripping unit, a

plurality of pipe-gripping dies mounted 'in'said grippingunit, anormallyi substantially. vertical-1y disposed pipe-receiving passage through said gripping unit and a universal joint operatively interconnecting said gripping unit and said supporting arm, said universal joint including a pair of substantially horizontal pivoting axes disposed at substantially right angles to one another.

9. A pipe wrench assembly including a pivoted pipe-gripping element having a forward face and a pipe engaging die having non-parallel pipe-engaging and rearward faces loosely mounted on said element with said rearward face disposed adjacent to said forward face. said forward and rearward faces being respectively concave and convex and substantially coinciding.

10. A pipe wrench assembly including a gripping unit having a pipe-receiving passage the-rethrough, a die finger carrier member disposed about said passage and rotatably mounted in said unit, means for rotating said carrier member in a forward direction, a plurality of die holding fingers pivotally mounted on said carrier member and extending in a direction forward of the center of said passage, a concave forward cam surface on the end of each of said fingers, a pipeengaging die having a pipe-engaging front face and a convex rear face loosely mounted on the end of each finger so that said rear face and said forward cam surface are complementary and disposed adjacent to one another, the distance between said faces being greater at one end of each die than at the other end and the end of each die having this greater face separation being the forwardmost end of the die when said fingers and said dies are in the pipe-engaging position, and means for simultaneously pivoting said fingers.

11. A pipe wrench assembly including a gripping unit having a pipe-receiving passage therethrough, three die holding fingers, each having a forward cam surface, pivotally mounted in said unit at regular intervals around said passage, means for pivoting said fingers and a pipeengaging die having a pipe-engaging face and a rearward face loosely mounted on the end of each finger, the distance between said faces being greater at one end than the other end of said faces and said forward cam surface and said rearward face being complementary and disposed adjacent to one another.

12. A pipe wrench assembly including a reversible source of rotary power, a ring gear, a

drive connection including a flexible shaft between said source of power and said ring gear, a pivoted pipe-gripping member rotatable on its pivot by said ring gear and a plurality of pipegripping dies mounted on said pipe-gripping member, said dies being disposed on opposite sides of a line between the axis about which said pipe-gripping member is pivoted and the central axis of a pipe which is to be gripped by said pipe-gripping dies.

13. A pipe wrench assembly including a ring gear, a reversible fluid-driven motor operatively connected to said ring gear to drive said ring gear in either direction, a pivoted pipe-gripping member rotatable on its pivot by said ring gear and a pair of pipe-gripping dies mounted on said pipe-gripping member, said dies being disposed on opposite sides of a line between the axis about which said pipe-gripping member is pivoted and the central axis of a pipe which is to be gripped by said pipe-gripping dies.

DAVID R. CORMANY.

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